Open and close ?les for writing, C/C++ Programming

If you have computed a number (stored as a ?oating-point value) and want to display this on a plot (i.e. as a character string) you have to convert it into a STRING. That is we want to convert between the two forms:

x_number=4.367

x_string='4.367'

the ?rst is a ?oating point number (suitable for plotting or mathematical computation), and the latter is a 5-char string array (suitable for display using title or text commands, or which can be written to a ?le). For quick tasks MATLAB includes commands num2str, str2num, int2str and some others which can convert from numbers (?oating point or integer) to strings and vice versa but for best results one should learn how to use printf/scanf family of functions.

Note: One very important useage of fprintf is in program debugging. Adding in fprintf statements at crucial places in the program allows you to display the values of variables in a clean and elegant way without ?lling up the screen with numbers (which is what often happens when you simply remove the ; from the end of a line). We begin with fprintf, which outputs strings to the screen (sprintf works basically the same way but outputs data to a matlab variable, sscanf and fscanf read from strings or ?les). Here is a typical usage:>>fprintf('\nthis number %d and this one %.4f and these characters: %s\n\n',... 4,3.6,'qwerty')this number 4 and this one 3.6000 and these characters: qwerty  fprintf and sprintf take as ARGUMENTS a string containing a mix of characters and FORMAT SPECI-FIERS, followed by a number of variables (here their values are explicitly shown ). Format speci?ers begin with a '%', and end with a CONVERSION CHARACTER. There are lots of conversion characters but the ones you will use most are d for integers, e, f, and g for ?oating point numbers, and s for string data. Between the '%' and the conversion character there are various optional parameters, but most of the time you only need to use either a width (single number giving number of characters to use), and/or a precision after a decimal point (number of digits to right of '.'). If you don't specify these then MATLAB will try to do something sensible. The \n symbol represents a special 'non-printing' character - the CARRIAGE RETURN. It is non-printing because it isn't a letter or number, but it is used to say that the line has ended and the next characters will be on a new line.

Posted Date: 3/19/2013 3:23:47 AM | Location : United States







Related Discussions:- Open and close ?les for writing, Assignment Help, Ask Question on Open and close ?les for writing, Get Answer, Expert's Help, Open and close ?les for writing Discussions

Write discussion on Open and close ?les for writing
Your posts are moderated
Related Questions
give an example of function

#questionhow can i add new customer and alot him a new unique id ..

# include stdio.h> # include conio.h> # include math.h>   void main () { int a=1,sqr=0,cube=0; clrscr (); while (a { sqr=pow(a,2); cube=pow(a,3);

Write a program to find the area under the curve y = f(x) between x = a and x = b, integrate y = f(x) between the limits of a and b. The area under a curve between two points can b

Specifying a Class: As discussed a class is defined to develop an algorithm and bind it together in a core shell. A class is an abstract data type (ADT).  The binding of dat

- But with less features and more user-friendly (particularly for non-tech savvy users). - Software needed having a left menu with links (no pictures required) for every hardwar

Write out pseudocode for a function called "and" that takes two arguments, both booleans, and returns the logical and of the inputs. DO NOT use the logical and operator: instead, w

Write a program that reads a line of characters from the user and displays that entire line after converting any uppercase characters to lowercase also change any lowercase charact

what is the function of spanning tree in graph algorithm?